The contribution of 3-D object height and density to altitude maintenance in low-altitude flight

Gray, Rob; Geri, George A.; Akhtar, Shama C.; Covas, Christine M.

doi:10.1167/4.8.843

Cited by 6 publications

(1 citation statement)

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“…This general type of arrangement—involving suppressive interactions—is sometimes referred to as ‘cross-channel’ masking. There is also good psychophysical support for this model from a dual-masking paradigm (Ross et al 1993; Foley 1994; Holmes and Meese 2004), from contrast matching (Meese and Hess 2004), from experiments involving fine-pattern discriminations (Olzak and Thomas 1999), and from the analysis of the slope of the psychometric function (Meese and Holmes 2007; Meese et al 2008). See Meese and Holmes (2007, 2010) for details and reviews.…”

Section: Introductionmentioning

confidence: 96%

A Reevaluation of Achromatic Spatio-Temporal Vision: Nonoriented Filters are Monocular, They Adapt, and Can be Used for Decision Making at High Flicker Speeds

Meese

Baker

2011

i-Perception

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Masking, adaptation, and summation paradigms have been used to investigate the characteristics of early spatio-temporal vision. Each has been taken to provide evidence for (i) oriented and (ii) nonoriented spatial-filtering mechanisms. However, subsequent findings suggest that the evidence for nonoriented mechanisms has been misinterpreted: those experiments might have revealed the characteristics of suppression (eg, gain control), not excitation, or merely the isotropic subunits of the oriented detecting mechanisms. To shed light on this, we used all three paradigms to focus on the ‘high-speed’ corner of spatio-temporal vision (low spatial frequency, high temporal frequency), where cross-oriented achromatic effects are greatest. We used flickering Gabor patches as targets and a 2IFC procedure for monocular, binocular, and dichoptic stimulus presentations. To account for our results, we devised a simple model involving an isotropic monocular filter-stage feeding orientation-tuned binocular filters. Both filter stages are adaptable, and their outputs are available to the decision stage following nonlinear contrast transduction. However, the monocular isotropic filters (i) adapt only to high-speed stimuli—consistent with a magnocellular subcortical substrate—and (ii) benefit decision making only for high-speed stimuli (ie, isotropic monocular outputs are available only for high-speed stimuli). According to this model, the visual processes revealed by masking, adaptation, and summation are related but not identical.

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Section: Introductionmentioning

confidence: 96%

A Reevaluation of Achromatic Spatio-Temporal Vision: Nonoriented Filters are Monocular, They Adapt, and Can be Used for Decision Making at High Flicker Speeds

Meese

Baker

2011

i-Perception

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Contrast normalization in colour vision: the effect of luminance contrast on colour contrast detection

Mullen

Kim

Gheiratmand

2014

Sci Rep

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While contrast normalization is well known to occur in luminance vision between overlaid achromatic contrasts, and in colour vision between overlaid colour contrasts, it is unknown whether it transfers between colour and luminance contrast. Here we investigate whether contrast detection in colour vision can be normalized by achromatic contrast, or whether this is a selective process driven only by colour contrast. We use a method of cross-orientation masking, in which colour detection is masked by cross-oriented achromatic contrast, over a range of spatio-temporal frequencies (0.375–1.5 cpd, 2–8 Hz). We find that there is virtually no cross-masking of colour by achromatic contrast under monocular or binocular conditions for any of the spatio-temporal frequencies tested, although we find significant facilitation at low spatio-temporal conditions (0.375 cpd, 2 Hz). These results indicate that the process of contrast nornalization is colour selective and independent of achromatic contrast, and imply segregated chromatic signals in early visual processing. Under dichoptic conditions, however, we find a strikingly different result with significant masking of colour by achromatic contrast. This indicates that the dichoptic site of suppression is unselective, responding similarly to colour and luminance contrast, and suggests that dichoptic suppression has a different origin from monocular or binocular suppression.

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Exercise does not enhance short-term deprivation-induced ocular dominance plasticity: evidence from dichoptic surround suppression

Baldwin

Finn

Green

et al. 2020

Preprint

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The input from the two eyes is combined in the brain. In this combination, the relative strength of the input from each eye is determined by the ocular dominance. Recent work has shown that this dominance can be temporarily shifted. Covering one eye with an eye patch for a few hours makes its contribution stronger. It has been proposed that this shift can be enhanced by exercise. Here, we test this hypothesis using a dichoptic surround suppression task, and with exercise performed according to American College of Sport Medicine guidelines. We measured detection thresholds for patches of sinusoidal grating shown to one eye. When an annular mask grating was shown simultaneously to the other eye, thresholds were elevated. The difference in the elevation found in each eye is our measure of relative eye dominance. We made these measurements before and after 120 minutes of monocular deprivation (with an eye patch). In the control condition, subjects rested during this time. For the exercise condition, 30 minutes of exercise were performed at the beginning of the patching period. This was followed by 90 minutes of rest. We find that patching results in a shift in ocular dominance that can be measured using dichoptic surround suppression. However, we find no effect of exercise on the magnitude of this shift. We further performed a meta-analysis on the four studies that have examined the effects of exercise on the dominance shift. Looking across these studies, we find no evidence for such an effect.

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The contribution of 3-D object height and density to altitude maintenance in low-altitude flight

Cited by 6 publications

References 0 publications

A Reevaluation of Achromatic Spatio-Temporal Vision: Nonoriented Filters are Monocular, They Adapt, and Can be Used for Decision Making at High Flicker Speeds

A Reevaluation of Achromatic Spatio-Temporal Vision: Nonoriented Filters are Monocular, They Adapt, and Can be Used for Decision Making at High Flicker Speeds

Contrast normalization in colour vision: the effect of luminance contrast on colour contrast detection

Exercise does not enhance short-term deprivation-induced ocular dominance plasticity: evidence from dichoptic surround suppression

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